The Animal Genetics Core is an essential resource for the proposed studies of the DERC as a whole. The Core has provided and will continue to provide all the investigators in the Center and the external investigators with our NOD mice that have been carefully bred and housed in a specific pathogen free environment (SPF) to give a high incidence of spontaneous diabetes. With the Core's support, we have developed a number of transgenic and gcnc knockout mice on NOD genetic background by vigorously back-crossing the original transgenic and/or knockout mice to our NOD colony. The genetic effect on diabetes development is further enhanced by the ability to those over-express or knockout genes to test hypotheses related to the expression of or protection against disease. The Core has provided and will continue to provide all investigators with these transgenic or knockout NOD mice. The Transgenic Core has successfully developed the techniques recently to inject transgene DNA directly into the ova of NOD mice, and a few of the transgenic NOD lines generated by direct injection are also maintained in Animal Genetics Core and are available for all the investigators. Those various NOD transgenic and/or knockout mice have provided and will continue to provide new models of both accelerated disease and protected against diabetes. The genetic integrity of the mice in the Animal Genetics Core is routinely tested, and all the mice are housed in SPF microisolator cages and monitored for pathogens by serology regularly.